This invention relates to a forage harvester having a rotary cutterhead and a shear bar aligned therewith for the cutting of crop material between the cutterhead and the shear bar, the shear bar being movable away from the cutterhead to a deflected position to accommodate hard foreign bodies lodged between the cutterhead and the shear bar, and the shear bar being biased to its undeflected position.
An apparatus having similar features is disclosed in German Patent or Auslegeschrift 1,268,422 in which the shear bar is maintained in its undeflected position by a spring-loaded locking member which is forced aside when the shear bar is deflected by a hard body, such as a stone, which has found its way with the crop to the cutterhead. After overcoming the spring-loading on the locking device in this way, the shear bar is free of the locking member and the cutting action ceases. Before cutting can be restarted, the shear bar must be moved manually back to its undeflected position and the locking member must be reset in its original position.
This is clearly a time-consuming procedure and the present invention enables considerable time to be saved.